When an object in motion is shot by an imaging apparatus, the subject has hitherto been shot as a blurred image without sharpness as a shutter speed increases. This is caused because the subject moves during the period of opening the shutter, i.e., during the exposure, and the movement is recorded as one image.
A technique is recently in widespread use that oscillates a lens or an imaging element to reduce blurring if an imaging apparatus moves. However, this method is inapplicable to the case where a certain subject moves. This is because the background does not move while the subject moves.
Patent Document 1 discloses a shooting method in which an image is recorded when the movement of the subject is not detected by comparing a first image and a second image taken at different moments. However, this method is applicable to take an image with less motion blur when a stationary object is shot, but not applicable to shoot a moving object.
Techniques for shooting a subject in motion without blurring include those disclosed in Patent Document 2, for example. In those techniques, a motion vector is detected from two consecutive images and a shutter speed is changed depending on the amount thereof to acquire a less blurred still image.